For the study, the researchers analysed the findings of 563 multiple trauma patients who had both chest CT and plain film X-rays performed.

They found that the X-rays missed 40% of clinically significant thoracic injuries, including lung contusions, lung lacerations, rib and spine fractures and air or blood trapped in the space between the lung and chest wall.

"The average multiple trauma patient, say from a fall or motor vehicle accident, will get a head CT, cervical spine CT, chest CT, abdomen CT and pelvic CT, basically from head to thighs,” said Robert A. Novelline, MD, senior author of the study.

"Today this takes about three to five minutes - 10 years ago it would take two hours, but the newest generation of CT scanners, called multidetector CT (or MDCT) has revolutionised the imaging of multiple trauma patients,” he added.

However, say the researchers, multiple trauma patients also first receive portable chest X-rays upon entry into the emergency department. "A doctor would get the chest X-ray done, and then order a CT, but tell the radiologist to omit the chest part of the CT because the X-ray was already performed and showed no problems for the patient. We wanted to see if avoiding chest CTs for this reason was really a good idea,” said Novelline.

According to the researchers, 49 million patients entered trauma centers last year, each of whom received an average of one imaging procedure apiece. Of those imaging procedures, 25-30% were CT scans.

"Some are saying that we are imaging too much, but this study shows that for optimum care of trauma patients high-tech imaging like MDCT is worth it and needs to be performed,” said Novelline.